DES MOINES (DTN) -- More than a year after the first case of porcine epidemic diarrhea virus showed up in U.S. pork herds, the disease has a strong foothold in the country and is proving difficult to control.

A year ago, the industry had reported PED cases in 103 barns across 11 states. This year, more than 4,700 cases have been found in 30 states. Between 150 and 200 positive cases are found each week.

Anecdotally, it looks like the disease has peaked, but the weekly volume of confirmed cases remains high. Industry veterinarians told reporters Wednesday at the World ...